From 99b847478c35b64ffddaf7af53c348217d037cb2 Mon Sep 17 00:00:00 2001 From: Alan Modra Date: Sat, 18 Mar 2023 16:34:08 +1030 Subject: [PATCH] XCOFF archive sanity check XCOFF archive elements are in a linked list. Add a little more sanity checking. This of course doesn't stop the fuzzers finding a way to make a loop, but this check is cheap. * coff-rs6000.c (_bfd_xcoff_openr_next_archived_file): Sanity check that next element isn't pointing back to the header. --- bfd/coff-rs6000.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/bfd/coff-rs6000.c b/bfd/coff-rs6000.c index 4b7b5d315df..735d434951e 100644 --- a/bfd/coff-rs6000.c +++ b/bfd/coff-rs6000.c @@ -1714,8 +1714,11 @@ _bfd_xcoff_openr_next_archived_file (bfd *archive, bfd *last_file) laststart -= SIZEOF_AR_HDR + arel->extra_size; } - /* Sanity check that we aren't pointing into the previous element. */ - if (filestart != 0 && filestart >= laststart && filestart < lastend) + /* Sanity check that we aren't pointing into the previous element, + or into the header. */ + if (filestart != 0 + && (filestart < SIZEOF_AR_FILE_HDR + || (filestart >= laststart && filestart < lastend))) { bfd_set_error (bfd_error_malformed_archive); return NULL; @@ -1747,8 +1750,11 @@ _bfd_xcoff_openr_next_archived_file (bfd *archive, bfd *last_file) laststart -= SIZEOF_AR_HDR_BIG + arel->extra_size; } - /* Sanity check that we aren't pointing into the previous element. */ - if (filestart != 0 && filestart >= laststart && filestart < lastend) + /* Sanity check that we aren't pointing into the previous element + or into the header. */ + if (filestart != 0 + && (filestart < SIZEOF_AR_FILE_HDR_BIG + || (filestart >= laststart && filestart < lastend))) { bfd_set_error (bfd_error_malformed_archive); return NULL; -- 2.30.2